Hairbrush



FIG. 1 is a top, rear and right side perspective view of a hairbrush showing the new design;

FIG. 2 is a top elevational view;

FIG. 3 is a right side elevational view;

FIG. 4 is a bottom plan view;

FIG. 5 is a left side elevational view;

FIG. 6 is a rear elevational view; and,

FIG. 7 is a front elevational view. 

The ornamental design for a hairbrush, as shown. 